Adhesive or binder



Patented Dec. 8, 1925;

1,565,027 UNITEDYSTATES PATENT OFF-ICE.

FRANCIS G. OKIE, OF ST. PAUL, MINNESOTA, ASSIGNOR TO MINNESOTA MINING 6cMANUFACTURING COMPANY, on ST. MINNESOTA;

PAUL, MINNESOTA, A CORPORATION OF ADHESIVE on BINDER.

No Drawing. Original application filed March 4:1922, Serialilto.541,249. Divided and this application To all whom it may concern:

Be it known that I, FRANCIS G. (nun, a citizen of the United States, anda resident of St. Paul, Ramsey County, Minnesota, have invented certainnew and useful Improvements in Adhesives or Binders, of

' tinuation of my prior application Serial No.

428,287, filed December 4, 1920, and a division of my prior applicationSerial No. 541,-

249, filed March 4, 1922.

Although I hereinafter disclosethe practice of my invention inconnection with tures thereof, have a wider field of utility;

Composite structures of the abrasive type such as sand-paper or emerycloth comprise generally (a) a base of sheet material, which may befelted as in the case of paper or woven as in the case of cloth, (6) amore or less finelycomminuted resistant material having abradingproperties, such as garnet or corundum, and (a) a binder generally inthe form of a glue which serves to bind the abrasive to "the base.

The abrasive products as produced at present have as incidents certainfeatures among sibility to accommodate itself to flexion of the base;the provision of a binder by means of which the desired adhesiveactionbetween it and the base is attained not only efliciently but alsowi h a desirable degree of accelerafiled October 24, 1923. Serial No.670,541.

tion, and more particularly the provision of a binder in which thedrying action will be effective from the contact surface between it andthe base outwardly; the provision of a binder in which the drying actionwill be eifectiveflfrom the outer surface inwardly the provision ofa'bindercharacterized by a drying action that permits of handling theproduct with a minimum of delay and more particularly such handlingwithout impairment of the superficies of the material; the provision ofa binder characterized by a limitation of its drying action; theprovision of an improved moisture-proofing treatment for anaterial, andespecially material in a sheet form, and more particularly for causing amoisture proofing agent to penetrate into the material to an extentshort of exudation on an adjacent surface thereof; the provision of amoisture-proof composite abrasive structure; the provision in such anarticle of a'binder having moisture-proofing function's, andtheprovision generally of'an improved flexible waterproof composite abra-fsive structure, together with such other objects and additional benefitsand advantages as may. hereinafter appear or be pointed out.

In the employment of my present invention for the production ofsand-paper and the like (which I cite for pu'rposesrof ex-.

ample) I use as the base such a, sheet of material (which may be paper)as will conveniently serve the employment contem plated, and as theabrasive such comminuted material (which may be crushed garnet)similarly adapted to serve the function in Y view.

It is desirable thatthe binder utilized.

have the functions and characteristics not only of great 'mechanicalstrength and of liarly ada ted for the attainment of these ends and t atgums or resins such, as kaur1,-

copal, dammar are examples of these types.

Gum dammar is preferredby me as best attaining the desired end s ,v1ewedfrom certain aspects In preparin the binder for use, the gum or resin isuse in connection with a suitable vehicle which I prefer is of a typesuch as linseed oil or china wood oil, for reason which I will proceedto explain.

In apply'ing'a gum or resin prepared with a veh1c1e such as linseed Ollto one surface of a base of paper for example I have found that theaction of the vehicle involves a penetration of the base by the vehicle,for

example linseed oil,'to a point which approxiin'ates the oppositesurface of the sheet but falls short of actual exudation of the vehicleupon such opposite surface.

This results in a moisture-proofing of the material againstthedestructive. absorption of moisture through the surface opposite tothat to which the binder is applied, without at the same time defacingor otherwise undesirably affecting such opposite surface.

This penetration by the vehicle, particularly when coupled with the useof the character of gum or resin pointed out above,

"carries with it in such'penctration a certain amount of finely dividedgum or resin so that divided abrasive is then applied in such a' manneras to cause it to adhere to the binder.

In order to accelerate the adhesion between the binder and the base, Ihave dis covered it desirable to use with the binder a modifying agentthe action of which is to cause a desiccation of the binder initiated atthe contact surface of the binder with the base and effectiveoutwardly.

In my experience I have discovered that there are a number ofmaterials'having a metallic base which are useful for mypresentpurposes, that manganie oxides are peculiarly useful and thatborate of manganese best combinates siccative energy with the'desirablesusceptibility to fine grinding.

Due to the relatively slow drying of binders generally difficulties areencountered in handling the structure, within a convenient periodbecause of the soft and sticky chara'cter particularly of the exposedsurfaces of the binder. This objection I mitigate by associating withthe improved binder a substance theaction of which is to produce anaccelerateddrying action efi'ective primarily at. the exposed surfaceand working inwardly, and for this purpose I incorporate in the binderamodifying'element peculiarly .as gum dammar are effective in its actionas an oxidizing agent on such vehicles as linseedoil and as apenetration retarding agent with reference to the excess absorption ofthe vehicle by the base.

The substance I have discovered to be particularly adapted for thispurpose is that carbonate of lead or white lead well known to the trade,obtainable in the open market and formed by a new electrolytic processand which in lny experience is found to .be more satisfactory than anyother known form of carbonate of lead.

'hereas by itself the white lead adds but relatively little strength tothe binder, in association in the binder with the borate of manganese itintensifies the action of the binder in holding the abrasive tirnilyagainst the base.

For intensifying the binding action of the binder and for intensifyingthe drying action of the dryers, and at the same time accomplishing suchends by the employment of a material which is etficacious in holding themineral elements in suspension without loss of siccativeenergy orreducing the relative fluidity of the material, I have discovered thatit is advantageous to employ as part of the bindera past dryer. This maycomprise such substancesas sugar of lead and borate of manganesesuspended in a resinousvehicle but I find it preferable to form thepaste dryer so as to have the substances contained therein in the forinof sub-acetate of lead and resinate of manganese. I have found byexperience that the paste dryer should be somewhat in the nature ofcheesy butter, rather softer, and of a light brownish grey color.

As an auxiliary in (1) accentuating the adhesion of the binder to thepaper, (2) facilitating toa certain extent the spreading of the binder,and (3) modifying as desired the consistency of the binder as is usefulin cases where it is desired torender it more fluid, I have discoveredthat the use of a Such a dryer japan dryer is desirable.

from

characterized by relative freedom rosin, is prefer-a do. One form ofthis contains shellac, red lead, litharge, manganese oxid, burnt umber,gum, linseed oil and turpentine q. s.

In order to give the binder the desired bulk I preferably employ a'varnish con sisting largely of an oil which may be hardened such aslinseed oil boiled until it reaches nearly a solid state. As far asfeasible this should be as free as possible from glycerides and fattyacids.

The aforementioned gums or. resins, such preferably employed in the formof a varnish which is substantially three parts Batavia dammar, with twoparts kettle boiled linseed oil.

While gum copal and gum kauri in certain respects make more substantialbinders tions, or when'producing material for certain purposes, that itis desirable to incorporate in the binder a non-drying oil such ascastor oil or the like, for such-purpose.

Sand-paper made in accordance with the disclosure of my presentinvention is characterized by great flexibility without any.

adverse effects, such ascracking of the binder or base, or loosening ofone from the other; and great resistance to water, and moisturegenerally, and is highly resistant to deterioration in theprcsence offriction and moisture when used in a water-abrading operation. 7

The materials used by me as hereinabove described may be varied incharacter so as to va the characteristics of the\ binder from thestand-point of adhesiveness, nonhygroscopy, and flexibility. Where suchvariations in the use of materials is employed to produce, for instance,increased adhesion between the binder and the abrasive, such increasemay be attained, though Gum varnish 6 0416 Part ILBorate. of manganese6. .0416 Gum varnish 6 .0416 Part III; Dryer; 6 041,6

Paste dryer 6 a .0416

Linseed oil varnish 48 3333 possibly at acertain expense of itscharacteristic of flexibility.

Due, however, to this very same increased adhesiveness, one or more ofthe outer layers of the base may be removed as by the em-v ployment of abase'which involves the use of a built up structure having a number ofplies, certain of which may be removed, or by shaving off part of thethickness of the base.

B this process I am enabled to obtain san paper characterized byextraordinary thinness and flexibility, in that I am able to formsand-paper and the like with a base so thin that such product could notbe manufactured, if the base originally used were of the thinnessultimately desired.

In my preferred. practice, I form batches which by weight and percentagecontain the following ingredients: 7

Pounds. c ii t.

Part ,I. Carbonate of lead 24 .1666

This gives a composition of matter wherein metallic and resinous basesare com bined in the proportions of substantially one to three; forinstance, from above formula:

Parts.

Gum varnish 6 White lead 24 Gum varnish 6 Borate of manga- Gum varnish42 nese 6 Linseed oil var- Dryer 6 nish 48 Dryer 6 36 The foregoingassumes that 6: parts of each of the japan and paste dryers are, di-

vided to the metallic and resinousbases.

In such preferred practice, Parts I and II are mixed and milledseparately since Part I mills more readily than Part II, and aredesirably then mixed with Part III and the composite batch is thenmilled until smooth. '7

Parts I and II include the gum varnish in order to'atta'n not only afinesubdivision of the, metallic substance but also to render themreadily commiscible with Part III.

In the preferred practice of my invention, in forming Part I hereinabovereferred to, I grind the carbonate of lead and the varnish to anexceeding fineness which may be accomplished by passing them through afine-grinding mlll three or four trips. The material grinds quickly andeasily'and may be conveniently mixed in the mill. One of the functionsof the carbonate of lead is to hasten the oxidization of the thinner(and greasier) elements 'of the binder and limit their absorption by thebase, e. g., paper in the case of-sand-paper.' It also hastens oraccelerates the superficial top-drying of the sand-paper or the like,rendering it among other things easier to handle before it becomes dry.Ordinary white leads, even- "though of apparent equal purity and ofsimilar analyses as that herein referred to, do not function assatisfactorily for chemical reasons not yet brought to light by myexperience.

Gum varnish may be No. 1 gum kauri, gum copal, or gum dammar or more orless numerous similar suitable gums or resins melted in boiled or rawlinseed oil, with or without the presence of dryers, such as red lead,litharge, black oxid of manganese, burnt umber, and the like. The gumvarnish preferably, used by me in Parts I, II and III above referred to,is substantially equal parts Bate iadammergum, and kettle boiled linseedoil. While I'preferably use gum dammar, as just indicated, I'have founda gum dammar varnish made from three parts Batavia dammar, melted byitself under. gentle heat, as is-preferable though it may be used cold,and two parts ofl a hydrocarbon (which may be one of the petroleumseries), obviously added after the a heat, if used, is discontinued. Thehydrocarbon referred to preferably takes the followin form:

%olor, water white; Baum, 48-49; initial boiling point not below 275 F.;not more than 50% over at 340 F.; recovery, at least 95% residue,colorless; end point, below 475 F. p Y

As the hydrocarbon evaporates, it may be advisable to add more to themixture in order to preserve the desired degree of fluidity. Thehydrocarbon dammar varnish thus formed makes a more brittle binder than'the linseed oil gum dammar warnish above described. Although gum copaland gum kauri each make a more substantial binder than gum dammar, asthey carry more oil and dry harder, they are'more expensive,

gum dammar not oxidizing to such a degree of hardness and toughness ismore highly flexible, but within my experience comprises as great a steptowards common rosin as at present advised it appears expedient to take.

I have found that synthetic gums or resins can also be used to goodadvantage in making a binder for my purposes.

In using borate of maganese I have found that a well-known borate ofmanganese, readily obtainable on the open market combines best siccativeenergy with susceptibility to fine grinding and to form Part II referredto above it should be ground in the varnish until it may be spread on aglass without being mealy under ones finger. It should be ground untilexperience shows that it can be ground no finer.

As willbe appreciated from the foregoing discussion, the siccativeenergy of the bo'rate of manganese operates from within outwardly,differing in this respect from the carbonate of lead which oxidizes fromwithout inwardly.

While Iprefer to employ manganic derivatives in the form of borate, ofmanganese, it is to be observed that although black oxide of manganesecontains certain desirable siccative elements for my purposes, it doesnot readily lend itself to grinding in such a manner as is desired byme. At times, advantage may be taken of the characteristics of blackoxide of manganese'by heating it in linseed oil.

Similarly, cobalt derivatives, (such as acetate of cobalt) may beemployed for their siccative qualities, but I have found that due careshould be employed in using such highly concentrated dryers so as toavoid any tendferred practice, I find it desirable to grind the borateof manganese by itself, ten or twelve trips if necessary, as this isrelatively a very hard substance to grind, and the varnish may be mixedtherewith in the mill.

The form of japan-dryer preferably employed by me is a well known japanwhich contains about 2% (two percentum) of shellac, preferably the bestobtainable, besides substances such as red lead (Pb O,; litharge. (PbO)man anese oxid (MnO- burnt umber (which as a manganic and oxygencontent) and ums in linseed oil and turpentine. It aids in thebinding-action and actsto'some extent as a thinner whose turpentinecontent evaporates after the binder is spread on the paper and somewhatfacilitates the spreading process. I have 'diflicult to handle, has beenfound by me in actual practice to be slightly better inv its functions.I

In preparing the paste-dryer of Part III above referred to, I first formthe initial portion of the dryer by stirring 200 pounds of litharge(PbO) and 2Q0,pounds, of hot water (120 F), the agitation of the waterbeing sufliciently violent during and after the addition of the lithargeto keep it from settling. After, say two to five minutes of thissustained-agitation, 45 pounds of 80% acetic acid is dashed into thehot-water and litharge composition without cessation of the violentstirrmg, which may be mechanical agitation, and which should continueuntil the milky white liquid that develops as soon sets to a consistencyresembling soft cottage cheese or-bonn'y clabber and ofi'erresistanceenough to 'tend'to slow up a strong man using a paddle.

In cases where a mechanical agitator is used, it should be shut off atthis stage which is ordinarily reached Within a minute after the aceticacid is dashed in. It is advisable to have the agitation sufiicientlyviolent to cause suspension of allof the litharge and to dash in theacetic acid suddenly, as otherwise a quantity of uncombined lithargewill be found at the bottom of the mixer, and the mass, which is nowbasic acetate of lead,

15" as the acid strikes the water and litharge,

will not set stifl. This resultant mass should be undisturbed for about15 hours and then ounds kettle boiled linseed oil is added to t ermass,which by this time has .become somewhat stiffer. The whole mass is thenmixed preferably in a mechanical mixer.

- The mixer should be run until a large perthat has been poured off. Thestrength of the acetic acid may be varied below 80% provided theproportions are changed correspondingly to the strength of the aceticacid.

While the second part of the paste dryer may be formed by heating, Iprefer to mix thoroughly pounds of kettle boiled linseed oil, with 7 5pounds of resinate of manganese (powdered form) and then grind themixture two or three trips until fine and smooth.

I then'add 225 poundskettle boiled linseed oil to the lead compoundformed in the mixer as above set forth, and then quickly mix theresulting mass of'the second portion. with the modified first or leadcompound portion which is in the mixer as'just set forth.

This mixing of the two portions should be done quickly because there isa nicely balanced proportion between the two, and an excess of eitherportion long contact with the other portion, imperfectly mixed, causes alivering and sometimes a separation therebet'ween. After this mixture ofthe two portions has stood for substantially an hour, they should bemilled one trip. This completes the paste dryer.

It should flowdown the apron of the mill about one inch deep, (more orless, depending partly on ti htness of rollers and consequent heat,) anit should be kept in stock in a consistency about like cheesy butter,but rather softer, and of a light brownish gray color. A

By having the manganic derivative precipitated or combined with a moresubstantial gum than rosin- (resinate of manganese) in the formation ofthis paste dryer results are attainable which from certain aspectspresent obvious advantages.

From the foregoin description it will be apparent that web thegeneralfunctions of the carbonate of lead is to serve as filler,

and of the borate of manganese, as well as of the japan compositionreferred to, .is to serve as a 6. er, and that the .rest of my improvedbin er is made up of varnishes.

for the oil than for.

The gross formula-of the binder'considered from this aspect of theinvention, therefore involves the use, generalli, of four parts filler,three parts dryer, and seventeen parts varnish, preferably associatedtogether in the specific manner set forth.

The binder is formed, in my preferred practice, by running togetherthrough the mill parts I and II, ground finely as de scribed, togetherwith the items of part III, 75 all three parts being milled togetheruntil the whole mass is uniform. and smooth.- The binder thus formedshould be kept carefully covered preferably in contact with oiled paperto prevent the formation of surface skin through exposure.

Having thus described my invention and illustrated its use, what I claimas. new. and desire to secure by Letters Patent is:

1. A waterproof adhesive including a mixture of substantially threeparts drier materials, four parts white lead, and seventeen partsvarnish material combined to render such adhesive stable and resistantto deterioration in the presence of friction and moisture when used in awater-abrading operation.

2. A waterproof binder for attaching grit to a surface for forming baseto form waterproof sandpaper, for employment in a water abradingprocess, which includes a mixture of varnish, drier and filler materialsafl'ording an inert binder for attaching the grit to the base andresisting rapid deterioration of such binder when employed in a 100water abrading operation.

3. A waterproof binder for sandpaper which is characterized byflexibility when solidified, substantial inertness, and possessingtenacity and durabilitysutficient to substantially resist rapiddeterioration in the presence of friction and moisture when employed ina water abrading process, said inder including varnish, drier and fillermaterials and having the'dual properties of affording a tenaciousretaining means for the grit and to permeate'the base for rendering. thelatter waterproof.

4. .A waterproof adhesive for bonding grit to a surface forming basetoform with such base an article in the nature of flexible waterproofsandpaper, said adhesive including an oil which when hardened is of anature to maintain its bonding effect when said adhesive is subjected tofriction even under sustained application of or immersion in water, saidadhesive being flexible when 5. A waterproof adhesive for bonding grit'to a surface forming base to form with such base an article in .thenature of flexible waterproof sandpaper, said adhesive including a gumwhich is ofa nature to maintain its bonding effect when id adhesive issubjected to friction even an er sustained ap- .139

jected to friction even under sustained ap-.

plication of or immersion in ivater, said adhesive being flexible whendry.

, 7. A waterproof adhesive for bonding grit to a surface forming base toform with such base an article in the nature of flexible waterproofsandpaper, said adhesive'including a gum varnish which is of a nature tomaintain its bonding effect when said adhesive is subjected to frictioneven under sustained application of or immersion in water, said adhesivebeing flexible whendry. .8. A waterproof adhesive for bondinggrit to asurface forming base to. form with such base an article in the nature offlexible waterproof sandpaper, said adhesive including the combinationof an oil and. a resin which combination is of a nature to maintain itsbonding effect when saidadhesive is subjected to friction even undersustained application of or immersion in water, said adhesive beingflexible when dry. 9. A waterproof adhesive for bonding grit to asurface forming base to form with such base an article in the nature offlexible waterproof sandpaper, said adhesive being of a nature tomaintain its bonding effect when said adhesive is subjected to frictioneven under sustained application of or'immersion in water said adhesivebeing flexible when dry and including a base material which is flexibleand waterproof and a penetration retarding agent. v

10. A waterproof adhesive for bonding grit to a surface forming base toform with such base an article in the nature of flexible waterproofsandpaper, said adhesive being vof a nature to maintain its bondingefiect when said adhesive is subjected to friction even undersustained'application of or immersion in water said adhesive beingflexible when dry and'including a base material which is flexible andwaterproof and a desiccating agent.

11. A waterproof adhesive for bonding grit to a surface forming base toform with suchbase an article in the nature of flexible waterproofsandpaper, said adhesive being of a nature to malntain. its bondingeffect when said adhesive is subjected to friction even under sustainedapplication of or immersion in water said adhesive being 'flexible whendry and including a base materialwhich is flexible and waterproof and adesiccation retarding agent.

12. A waterproof adhesive. for bonding grit to a surface forming base toform. with such base an article in the nature of flexible waterproofsandpaper, said adhesive being of a nature to maintain its bondingeffect when said adhesive is subjected to friction even under sustainedapplication of or immersion in water said adhesive being flexwhich isflexible and waterproof, penetration retarding agent and a desiccatingagent.

14. A waterproof adhesive for bonding grit to a surface forming base toform with' such base an article in the nature of flexible waterproofsandpaper, said adhesive being of a nature tomaintain its bondin efiectvfriction when said adhesive is subjected to even under sustainedapplication of or immersion ,in water said adhesive being-flexible whendry and including as a base material which is flexible and waterproof,the combination .of a desiccating agent which accelerates the 'drying ofthe adhesive from the surface which is in contact with the air.

15. A waterproof adhesivefor bonding grit to a surface forming base toform'with such base an article in the nature of flexible waterproofsandpaper, said adhesive being of a nature to maintain its bondingeffect when said adhesive is subjected to friction even under sustainedapplication of or immersion in water said adhesive being flexible whendry and including as a base material ible when dry and including a basematerial 4 which is flexible and waterproof, the combination of adesiccating agent which accelerates the drying of adhesive from thesurface which is out of contact with air and in contact with the.article to which the adhesive is applied.

16.--A waterproof "adhesive for bonding grit to a surface forming baseto form wit such base an article in the nature of-flexible waterproofsandpaper, said adhesive being of a nature to malntain its bondingeffect when said adhesive is'subjected to friction even under sustainedapplication of or im-. mersion in water said adhesive being flexiblewhen dry and including as a base material which is flexible andwaterproof, the combination of a plurality of desiccating agents one ofwhich accelerates the drying of the adhesive from the surface which isin contact with the air, and another of which accelerates the drying ofthe adhesive from the surface which is out of contact with air and incontact with the article to which the adhesive is applied.

17 A waterproof adhesive bonding grit to a surface forming' base to formwith such base an article in the nature of flexiblewaterproof sandpaper,said adhesive being of a nature to maintain its bonding efiect when saidadhesive is subjected to friction.

even under sustained application of or immersion in-water said adhesivebeing flexible when dry and including as a base material which isflexible and waterproof, the combination of a desiccating agent whichaccelerates the drying of adhesive from the surface which is out ofcontact with air and in contact with the article to which the adhesiveis applied, and a penetration retard-- ing agent.

18. A Waterproof adhesive for bonding grit to a surface forming base toform with such base an article in the nature of flexible waterproofsandpaper, said adhesive-being of a nature to maintain its bondingeffect when said adhesive is subjected to friction even under sustainedapplication of or immersion inwater, said adhesive being flexible whendry and including a base material wlliich is flexible and waterproof andcastor o1 20. A waterproof adhesive for bonding grit to a surfaceforming base to form with such base an article in the nature of flexiblewaterproof sandpaper, said adhesive being of a nature to maintain itsbonding effect when said adhesive is subjected to friction even undersustained application of or immersion in water, said adhesive beingflexible when dry and including a base material which is flexible andwater proof and borate of manganese.

21. A waterproof adhesive for bonding grit to a surface forming base toform with such base an article in the nature of flexible waterproofsandpaper, said adhesive being of a nature to maintain its bondingeflect when said adhesive is subjected to friction even under sustainedapplication of or immersion in water, said adhesive being flexible whendry and including a base material which is flexible and waterproof and8. japan dryer.

In testimony whereof I have hereunto signed my name.

FRANCIS G. OKIE.

